The ____________ kick is performed from a horizontal position with knees bent at 90 degrees featuring a scissor movement.

The kick that is described as being performed from a horizontal position with knees bent at 90 degrees and featuring a scissor movement corresponds to the Modified Frog kick. This kick is characterized by the legs moving apart and together in a manner similar to a frog's movement, but the knees maintain a 90-degree angle which engages the inner thighs and provides efficient propulsion while minimizing turbulence in the water.

The Modified Frog kick is specifically advantageous in cavern diving situations where maintaining a streamlined profile is essential for avoiding silt and keeping visibility clear. It allows a diver to maneuver through tight spaces with control, making it a preferred technique in environments where traditional kicks might be less effective. This kick also facilitates better buoyancy control, which is crucial in overhead environments where divers are not accustomed to descending or ascending rapidly.

Other kick techniques mentioned, such as the Frog kick or Paddle kick, may vary in their execution and application but do not fit the specific criteria of the scissor movement described in the question. The Shuffle kick, while used in some contexts, does not involve the same knee positioning and movement dynamics as the Modified Frog kick.